Jenna Jameson "gained 20 pounds(9kg)" after taking a break from her keto diet, which she had previously praised for helping her shed 85 pounds(38.5kg).

The 45-year-old star had previously hailed the diet for helping her shed a whopping 85 lbs., but after taking a short break from the plan - which is a low-carb, high-fat diet - to live her "best carby life", she's put 20 lbs(9kg) back on.

Posting on Instagram, Jenna wrote: "Confession. I've gained 20 pounds. Ugh. I decided to take a break from #keto and live my best carby life. The weight came back fast and furious. I know a lot of people are quitting keto because it's hard to maintain and after a year and a half I concur. Not sure if I'm going to go back full force or just calorie count. What are your thoughts? Love you guys! (sic)"

Last year, Jenna shared a before and after picture of her face following her decision to go on the diet plan, as she highlighted how her new eating habits had helped her face appear less "puffy".

She wrote at the time: "I've never talked about how changing my diet has impacted the inflammation in my body. Not only has my face changed from weightloss, but eating whole foods and next to zero processed foods has made my skin better. Less puffiness, we all can go for that!

Jenna started the diet in March 2018 in an effort to lose the baby weight that stuck around after she gave birth to daughter Batel in April 2017.

Speaking about her weight loss in July last year, the retired adult film star - who has Batel with her partner Lior Bitton, as well as 10-year-old twins Jesse and Journey with her former husband Tito Ortiz - said: "I was lethargic and struggled with the easiest of tasks like walking in the beach sand with Batelli. I felt slow mentally and physically.

"I took the pic on the right for a body positive post I was going to do and decided against it because I felt anything but f***ing positive. I'm now a little under four months on the #ketodiet and it's not only given me physical results, I feel happier, smarter, and much more confident. (sic)"